>>48172946The reward obtained for any specific feat accomplished is not indicative of its importance.
The game literally speaks for itself in telling you that your goal is to help the professor complete the Pokedex. Battling in the league is just a means to that end, as recognition of being a strong trainer often grants you access to places deemed too dangerous for inexperienced trainers. This is a recurring theme throughout the series, and you mean to tell me that it's wrong because you get a cutscene and some music for beating the league?
Depending on the game, you get a cutscene and some music for encountering the box legendary, or even running into your rival.
But sure, the game is "complete" once you get free reign over the region, and not when you accomplish the task given to you when you start your journey.
